Antiviral dendrimers

ABSTRACT

An antiviral compound comprises a dendrimer such as a polyamidoamine or polyly sine dendrimer having a plurality of terminal groups, wherein at least one of the terminal groups has an anionic- or cationic-containing moiety bonded thereto, particularly a sulfonic acid-containing, carboxylic acid-containing or trimethylammonium-containing moiety or the like.

FIELD OF THE INVENTION

This invention relates to antiviral agents, and in particular it relatesto dendrimers which have been found to have significant antiviralactivity against human immunodeficiency virus (HIV) and other envelopedviruses.

BACKGROUND OF THE INVENTION

It has been established that certain sulfonated polysaccharide compoundshave antiviral activity when screened against HIV, however thesecompounds are relatively unstable and accordingly large amounts of thesecompounds are required to obtain effective antiviral effects. Inaddition, many of these compounds, including heparin and dextran sulfatefor example, are potent anticoagulants and because of this activity theyare not particularly suited for clinical use as antiviral agents.

The present invention provides a new class of antiviral agents based ona particular type of polymer referred to herein as a “dendrimer”, whichhave substantial antiviral activity against HIV1 and HIV2, CMV and HSV,and which have substantially no anticoagulant activity. These compoundsare therefore well suited for prophylactic and therapeutic use asantiviral agents in humans.

SUMMARY OF THE INVENTION

According to the present invention, there is provided an antiviralcompound comprising a dendrimer having a plurality of terminal groupswherein at least one of said terminal groups has an anionic- orcationic-containing moiety, other than a 2-thiosialic acid moiety,bonded thereto.

Such a dendrimer is referred to here in as an “anionic or cationicdendrimer”, and this term is used throughout this specification and theclaims which follow to include not only the dendrimers per se, but alsotheir pharmaceutically or veterinarily acceptable salts, for example thealkaline metal or alkaline earth metal salts such as the sodium,potassium or calcium salts.

BRIEF DESCRIPTION OF THE DRAWING

FIG. 1 shows a dendrimer with bound ionic moieties Z.

DETAILED DESCRIPTION OF THE INVENTION

Dendrimers are macromolecular highly branched compounds formed byreiterative reaction sequences starting from an initial, core moleculewith successive layers or stages being added in successive “generations”to build up a three-dimensional, highly ordered polymeric compound. Ageneralised dendrimer structure is shown in FIG. 1. Dendrimers arecharacterised by the following features: i an initiator core(I) whichmay have one or more reactive sites and be point-like or of significantsize so as to effect the final topology of the dendrimer; ii layers ofbranched repeating units attached to the initiator core; iii functionalterminal groups(Z) attached to the surface of the dendrimer. The presentinvention uses dendritic structures as frameworks for the attachment ofionic moieties; the invention is not limited to the spherical dendrimersdescribed in detail herein but can be based on any dendritic structure.The variety of dendrimers in both shape and constitution are well knownto persons skilled in the art.

The preparation of dendrimers is well known, and is described by way ofexample in U.S. Pat. Nos. 4,289,872 and 4,410,688 (describing dendrimersbased on layers of lysine units), as well as U.S. Pat. Nos. 4,507,466,4,558,120, 4,568,737 and 4,587,329 (describing dendrimers based on otherunits including polyamidoamine or PAMAM dendrimers). The dendrimersdisclosed in these US patents are described as being suitable for usessuch as surface modifying agents, as metal chelating agents, asdemulsifiers or oil/water emulsions, wet strength agents in themanufacture of paper, and as agents for modifying viscosity in aqueousformulations such as paints. It is also suggested in U.S. Pat. Nos.4,289,872 and 4,410,688 that the dendrimers based on lysine units can beused as substrates for the preparation of pharmaceutical dosages.

International Patent Publications Nos. WO 88/01178, WO 88/01179 and WO88/01180 disclose conjugates in which a dendrimer is conjugated orassociated with another material such as a carried pharmaceutical oragricultural material. These patent publications together with the U.S.patents mentioned above contain a broad disclosure of various dendrimersand processes for the preparation thereof, and the disclosure of each ofthese publications is incorporated herein by reference.

The term “dendrimer” as used herein is to be understood in its broadestsense, and to include within its scope all forms and compositions ofthese dendrimers as disclosed in Patent Publications Nos. WO 88/01178,WO 88/01179 and WO 88/01180. The term also includes linked or bridgeddendrimers as disclosed in these patent publications.

The preferred dendrimers of the present invention comprise a polyvalentcore covalently bonded to at least two dendritic branches, andpreferably extend through at least two generations. Particularlypreferred dendrimers are polyamidoamine (PAMAM) dendrimers, PAMAM (EDA)dendrimers and polylysine dendrimers.

In accordance with the present invention, at least one, and preferably asubstantial number, of the terminal groups on the surface of thedendrimer has an anionic- or cationic-containing moiety covalentlybonded thereto. The branches of the dendrimer may terminate in aminogroups or other functional reactive groups such as OK, SH, or the like,which subsequently can be reacted with the cationic and anionic moietiesforming the outer layer of the dendrimer. Where the terminal groups ofthe dendrimer are amine groups, the anionic- or cationic-containingmoiety may be bonded to the dendrimer by a variety of functional groupsincluding amide and thiourea linkages. Preferred anionic- orcationic-containing moieties which may be bonded to the terminal groupsof the dendrimer include sulfonic acid-containing moieties, carboxylicacid-containing moieties other than 2-thiosialic acid moieties,trimethylammonium-containing moieties andpolyamino-macrocycle-containing moieties.

Suitable anionic- and cationic-containing moieties which may be bondedto the amino or other terminal groups of dendrimers include, by way ofexample, the following groups (in which n is zero or a positive integer,more particularly n is zero or an integer of from 1 to 20):

—NH(CH₂)_(n)SO₃ ⁻—(CH₂)_(n)SO₃ ⁻—Ar(SO₃ ⁻)_(n)

—CH₂CH(SO₃ ⁻)COOH—CH(SO₃ ⁻)CH₂COOH—ArX(CH₂)_(n)SO₃ ⁻(X═O,S,NH)

—(CH₂)_(n) ⁺NMe₃—Ar(N⁺Me₃)_(n)—Ar(CH₂N⁺Me₃)_(n)

Particular moieties which may be bonded to the terminal groups of thedendrimer in accordance with this invention include alkyl sulfonic acidgroups; supfoacetamide groups; sulfosuccinamic acid groups; N-sulfoalkylsuccinamide groups, such as N-(2-sulfoethyl)succinamide groups; aryl orheteroaryl thioureas substituted with one or more sulfonic acid groups,such as 4-sulfophenylthiourea groups, 3,6-disulfonapthylthiourea groups,4-sulfonapthylthiourea groups, 3,5-disulfophenyl thiourea groups and3,6,8-trisulfonapthylthiourea groups; aryl or heteroaryl amidessubstituted with one or more sulfonic acid, sulfoalkyl, sulfoalkoxy,sulfoalkylamino or sulfoalkylthio groups, such as 4-(sulfomethyl)benzamide groups or 4-sulfobenzamide groups; aryl or heteroarylalkanamides substituted with one or more sulfonic acid groups, such asN-(4-sulfophenyl) propanamide groups; aryl or heteroaryl ureassubstituted with one or more sulfonic acid groups, such as 4-sulfophenylurea groups; N,N,N-trimethyl derivatives of amino acids, such asN,N,N-trimethylglycinamine groups; aryl or heteroarylamides substitutedwith one or more trialkylamino, trialkylaminoalkyl,trialkylaminoalkyloxy, trialkylaminoalkylamino or trialkylaminoalkylthiogroups, such as 4-trimethylammonium benzamide or 4-(trimethylammoniummethyl) benzamide groups;N-(2-acetoxyethyl)-N,N-(dimethylammonium)methylcarboxamide groups;guanidino groups; 4-carboxy-3-hydroxybenzylamine groups; or macrocyclicpolyamino groups containing one or more macrocyclic rings connectedthrough an alkyl or aryl spacer moiety to the terminal group of thedendrimer, such as 4-([1,4,8,11-terayclotetradecane]methyl)benzamidegroups.

The anionic or cationic dendrimers of this invention may be prepared bystandard chemical methods which are well known to persons skilled inthis art. Suitable methods are described by way of example in Examples 1to 20 below.

As previously described, the anionic or cationic dendrimers of thepresent invention have been found to exhibit significant antiviralactivity, particularly against HIV. Accordingly, these anionic orcationic dendrimers are useful in prophylactic and therapeutic treatmentof viral infections, for example infections by HIV1 and HIV2 and otherenveloped viruses including flaviviruses such as Hepatitis B andHepatitis C, Bovine Viral Diarrhoea Virus, Human Influenza Virus A andB, Rhinovirus, Human Parainfluenza Virus, Respiratory Syncytial Virus(RSV), Varicella Zoster Virus (VZV), Human Cytomegalovirus (CMV),Epstein Barr Virus (EBV), Human Papilloma Virus (HPV), Adenovirus-8,Herpes Simplex Virus (HSV) type 1 and 2, Measles Virus, and VesicularStomatitis Virus (VSV).

Thus, in another aspect the present invention provides a pharmaceuticalor veterinary composition for prophylactic or therapeutic antiviraltreatment of a human or non-human animal, which comprises an anionic orcationic dendrimer as broadly described above, in association with atleast one pharmaceutically or veterinarily acceptable carrier ordiluent.

The formulation of such compositions is well known to persons skilled inthis field. Suitable pharmaceutically acceptable carriers and/ordiluents include any and all conventional solvents, dispersion media,fillers, solid carriers, aqueous solutions, coatings, antibacterial andantifungal agents, isotonic and absorption delaying agents, and thelike. The use of such media and agents for pharmaceutically activesubstances is well known in the art, and it is described, by way ofexample, in Remington's Pharmaceutical Sciences, 18th Edition, MackPublishing Company, Pennsylvania, USA. Except insofar as anyconventional media or agent is incompatible with the active ingredient,use thereof in the pharmaceutical compositions of the present inventionis contemplated. Supplementary active ingredients can also beincorporated into the compositions.

It is especially advantageous to formulate compositions in dosage unitform for ease of administration and uniformity of dosage. Dosage unitform as used herein refers to physically discrete units suited asunitary dosages for the human subjects to be treated; each unitcontaining a predetermined quantity of active ingredient calculated toproduce the desired therapeutic effect in association with the requiredpharmaceutical carrier and/or diluent. The specifications for the noveldosage unit forms of the invention are dictated by and directlydependent on (a) the unique characteristics of the active ingredient andthe particular therapeutic effect to be achieved, and (b) thelimitations inherent in the art of compounding such an active ingredientfor the particular treatment.

In another aspect, the present invention provides a method forprophylactic or therapeutic treatment of an HIV or other viral infectionin a human or non-human animal, which comprises administering to saidhuman or animal a prophylactic- or therapeutic-antiviral-effectiveamount of an anionic or cationic dendrimer as broadly described above.

In yet another aspect, this invention provides the use of aprophylactic- or therapeutic-antiviral-effective amount of an anionic orcationic dendrimer as broadly described above in the prophylactic ortherapeutic treatment of, or in the manufacture of a medicament forprophylactic or therapeutic treatment of an HIV or other viral infectionin a human or non-human animal.

A variety of administration routes are available. The particular modeselected will depend, of course, upon the particular condition beingtreated and the dosage required for therapeutic efficacy. The methods ofthis invention, generally speaking, may be practised using any mode ofadministration that is medically acceptable, meaning any mode thatproduces therapeutic levels of the active component of the inventionwithout causing clinically unacceptable adverse effects. Such modes ofadministration include oral, rectal, topical, nasal, transdermal orparenteral (e.g. subcutaneous, intramuscular and intravenous) routes.Formulations for oral administration include discrete units such ascapsules, tablets, lozenges and the like. Other routes includeintrathecal administration directly into spinal fluid, directintroduction such as by various catheter and balloon angioplasty deviceswell known to those of ordinary skill in the art, and intraparenchymalinjection into targeted areas.

The compositions may conveniently be presented in unit dosage form andmay be prepared by any of the methods well known in the art of pharmacy.Such methods include the step of bringing the active component intoassociation with a carrier which constitutes one or more accessoryingredients. In general, the compositions are prepared by uniformly andintimately bringing the active component into association with a liquidcarrier, a finely divided solid carrier, or both, and then, ifnecessary, shaping the product.

Compositions of the present invention suitable for oral administrationmay be presented as discrete units such as capsules, cachets, tablets orlozenges, each containing a predetermined amount of the activecomponent, in liposomes or as a suspension in an aqueous liquor ornon-aqueous liquid such as a syrup, an elixir, or an emulsion.

Compositions suitable for parenteral administration convenientlycomprise a sterile aqueous preparation of the active component which ispreferably isotonic with the blood of the recipient. This aqueouspreparation may be formulated according to known methods using thosesuitable dispersing or wetting agents and suspending agents. The sterileinjectable preparation may also be a sterile injectable solution orsuspension in a non-toxic parenterally-acceptable diluent or solvent,for example as a solution in polyethylene glycol. Among the acceptablevehicles and solvents that may be employed are water, Ringer's solutionand isotonic sodium chloride solution. In addition, sterile, fixed oilsare conventionally employed as a solvent or suspending medium. For thispurpose, any bland fixed oil may be employed including synthetic mono-ordi-glycerides. In addition, fatty acids such as oleic acid find use inthe preparation of injectables.

Other delivery systems can include sustained release delivery systems.Preferred sustained release delivery systems are those which can providefor release of the active component of the invention in sustainedrelease pellets or capsules. Many types of sustained release deliverysystems are available. These include, but are not limited to: (a)erosional systems in which the active component is contained within amatrix, and (b) diffusional systems in which the active componentpermeates at a controlled rate through a polymer. In addition, apump-based hardware delivery system can be used, some of which areadapted for implantation.

The active component is administered in prophylactically ortherapeutically effective amounts. A prophylactically or therapeuticallyeffective amount means that amount necessary at least partly to attainthe desired effect, or to delay the onset of, inhibit the progressionof, or halt altogether, the onset or progression of the particularcondition being treated. Such amounts will depend, of course, on theparticular condition being treated, the severity of the condition andindividual patient parameters including age, physical condition, size,weight and concurrent treatment. These factors are well known to thoseof ordinary skill in the art and can be addressed with no more thanroutine experimentation. It is preferred generally that a maximum dosebe used, that is, the highest safe dose according to sound medicaljudgement. It will be understood by those of ordinary skill in the art,however, that a lower dose or tolerable dose may be administered formedical reasons, psychological reasons or for virtually any otherreasons.

Generally, daily oral doses of active component will be from about 0.01mg/kg per day to 1000 mg/kg per day. Small doses (0.01-1 mg) may beadministered initially, followed by increasing doses up to about 1000mg/kg per day. In the event that the response in a subject isinsufficient at such doses, even higher doses (or effective higher dosesby a different, more localised delivery route) may be employed to theextent patient tolerance permits. Multiple doses per day arecontemplated to achieve appropriate systemic levels of compounds.

Throughout this specification and the claims which follow, unless thecontext requires otherwise, the word “comprise”, or variations such as“comprises” or “comprising”, will be understood to imply the inclusionof a stated integer or group of integers but not the exclusion of anyother integer or group of integers.

Further features of the present invention will be apparent from thefollowing Examples which are included by way of illustration, notlimitation of the invention. In the following Examples, PAMAM dendrimersrefer to polyamidoamine dendrimers based on an ammonia core as detailedin U.S. Pat. Nos. 4,507,466, 4,558,120, 4,568,737 and 4,587,329; PAMAM(EDA) dendrimers refer to polyamidoamine dendrimers based on an ethylenediamine core; and BHAlys_(x)lys_(y)lys_(z) dendrimers refer topolylysine unsymmetrical dendrimers based on a benzhydrylamine core andlysine branching units as described in U.S. Pat. Nos. 4,289,872 and4,410,688. The polyamidoamine dendrimers PAMAM 1.0, PAMAM 2.0, PAMAM3.0, PAMAM 4.0, PAMAM 5.0 or higher generation, PAMAM 4.0 (EDA), and thepolylysine dendrimers BHAlyslys₂, BHAlyslys₂lys₄, BHAlyslys₂lys₄lys₈ andBHAlyslys₂lys₄lys₈lys₁₆, BHAlyslys₂lys₄lys₈lys₁₆lys₃₂,BHAlyslys₂lys₄lys₈lys₁₆lys₃₂lys₆₄, or higher generations are prepared asdescribed in U.S. Pat. Nos. 4,289,872, 4,410,688, 4,507,466, 4,558,120,4,568,737 and 4,587,329 and International Patent Publications Nos. WO88/01178, WO 88/01179 and WO 88/01180 referred to above.

EXAMPLE 1

Reaction of polymers with 2-acrylamido-2-methyl propane sulfonic acid togive sulfonic acid terminated dendrimers.

A. PAMAM 1.0

Solid sodium carbonate (0.13 g; 1.0 mmol) was added slowly to a stirredsolution of 2-acrylamido-2-methyl propane sulfonic acid (0.41 g; 2.0mmol) in water (3 ml). After the evolution of gas had ceased, the pH ofthe solution was 8.0. A solution of PAMAM 1.0 (0.12 g; 0.33 mmol) inwater (1 ml) was then added to the solution followed by the addition offour drops of a 40% aq. solution of benzyl trimethylammonium hydroxide.The solution was then heated under nitrogen at 60° for three days andthen concentrated. The residue was purified by gel filtration (SephadexG10; water) and then freeze dried to give the sulfonated PAMAM 1.0dendrimer as an off-white solid (0.51 g). ¹H and ¹³C nmr spectra showeda mixture of dialkylated and monoalkylated PAMAM 1.0 dendrimer (ca.70:30). ¹³C nmr (D₂O): δ 31.0, 31.1, 37.1, 37.7, 41.3, 48.6, 51.5, 53.1,53.4, 55.6, 56.2, 61.2, 61.5, 178.3, 179.0, 179.8.

B. PAMAM 2.0 (Compound No. 20)

PAMAM 2.0 was reacted with 2-acrylamido-2-methyl propane sulfonic acidas described above. The crude product was purified by gel filtration(Sephadex G10; water) and then freeze dried to give an off-white solid.¹H and ¹³C nmr spectra showed a mixture of dialkylated and monoalkylatedPAMAM 2.0 dendrimer (ca 65:35). ¹³C nmr (D₂O): δ 31.0, 31.1, 37.1, 37.7,41.3, 48.7, 51.5, 53.4, 55.6, 56.2, 61.2, 61.5, 178.4, 179.0, 179.1,179.6. When the above reaction was repeated omitting thebenzyltrimethyl-ammonium hydroxide a similar result was obtained.

C. PAMAM 3.0

PAMAM 3.0 was reacted with 2-acrylamido-2-methyl propane sulfonic acidas above except that a slight excess of sodium carbonate was used andthe benzyltrimethylammonium hydroxide was omitted. ¹H and ¹³C nmrspectra showed a mixture of dialkylated and monoalkylated PAMAM 3.0dendrimer (ca. 50:50). ¹³C nmr (D₂O): δ 31.0, 31.1, 36.9, 37.4, 41.1,48.6, 51.5, 53.4, 55.7, 56.2, 61.1, 61.5, 178.2, 178.9, 179.0, 179.8.

D. PAMAM 4.0

PAMAM 4.0 was reacted with 2-acrylamido-2-methyl propane sulfonic acidas described for PAMAM 3.0. ¹H and ¹³C nmr spectra showed a mixture ofdialkylated and monoalkylated PAMAM 4.0 dendrimer (ca. 35:65). ¹³C nmr(D₂O): δ 31.0, 31.1, 36.9, 37.3, 41.1, 48.5, 51.5, 53.5, 55.7, 56.2,61.1, 61.5, 178.1, 178.9, 179.0, 179.8.

EXAMPLE 2

Preparation of sodium sulfoacetamide terminated dendrimers.

A. PAMAM 1.0

A solution of 4-nitrophenyl bromoacetate (0.40 g; 1.5 mmol) in dry DMF(1 ml) was added to a stirred solution of PAMAM 1.0 (0.18 g; 0.5 mmol)in DMF (3 ml). The resulting yellow solution was stirred for 20 hours atroom temperature, when a ninhydrin test was negative. The solution wasconcentrated (30°/0.1 mmHg) to give a yellow oil. This oil waspartitioned between water and chloroform and the aqueous layer separatedand washed with chloroform (2×) and finally with ethyl acetate. Theaqueous solution was concentrated (35° /25 mmHg) to give thebromoacetylated PAMAM 1.0 dendrimer as a yellow oil (0.36 g; 100% ). ¹³Cnmr (D₂O): δ 32.8, 33.3, 43.0, 43.5, 54.4, 174.5, 176.4.

A solution of sodium sulfite (0.2 g; 1.6mmol) in water (1 ml) was addedto a solution of the bromoacetylated PAMAM 1.0 dendrimer described above(0.36 g; 0.5 mmol) in water (5 ml) and the solution left to stand atroom temperature for eleven days. The yellow solution was concentratedto give a yellowish solid (0.60 g). ¹³C nmr (D₂O): δ 34.4, 43.1, 43.4,54.0, 61.7, 171.3, 177.2.

The above reaction sequence could be carried out without isolating thebromoacetylated dendrimer by simply adding the sodium sulfite solutionto the crude aqueous extract obtained from the first reaction.

B. PAMAM 2.0

Method 1:

A solution of 4-nitrophenyl bromoacetate (0.18 g; 0.7 mmol) in dry DMF(1 ml) was added to a stirred solution of PAMAM 2.0 (0.10 g; 0.1 mmol)in DMF (3 ml). The resulting yellow solution was stirred for 20 hours atroom temperature, when a ninhydrin test was negative. The solution wasthen added with swirling to water (150 ml) and the mixture extractedwith chloroform (3×) and ethyl acetate. A solution of sodium sulfite(0.1 g; 0.8 mmol) in water (1 ml) was added to the crude bromoacetylateddendrimer solution and the mixture allowed to stand for three days atroom temperature. The yellowish solution was then concentrated to give ayellow solid residue, which was purified by gel filtration (SephadexLH20; water) to give the sodium sulfoacetamide terminated PAMAM 2.0dendrimer (103 mg). ¹³C nmr (D₂O): δ 33.0, 35.7, 36.0, 37.7, 40.3, 43.0,43.2, 53.4, 53.7, 56.0, 61.6, 171.2, 174.6, 178.5.

Method 2:

Solid succinimidyl acetylthioacetate (67 mg; 0.33 mmol) was added to asolution of PAMAM 2.0 (52 mg; 0.05 mmol) in dry DMF (2 ml) and theresulting solution stirred at room temperature for two days. The mixturewas then concentrated (30°/10⁻³ mmHg) to give an oily residue. Theresidue was partitioned between water and chloroform, and the waterlayer separated and concentrated to give a viscous oil (117 mg). ¹H and¹³C nmr showed the oil to be a mixture of the acylated dendrimer andN-hydroxy succinimide. Gel filtration (Sephadex G10; water) provided apure sample of the acetylthioacetamide terminated PAMAM 2.0 dendrimer(29 mg). ¹³C nmr (D₂O): δ 34.0, 34.2, 37.3, 43.0, 43.1, 43.3, 53.5,54.0, 56.3, 175.4, 177.2, 177.5.

A solution of the above functionalised dendrimer in 40% aqueous formicacid (7 ml) was then added to an ice cold freshly prepared solution ofperformic acid (1.6 mmol) in formic acid (2 ml). The mixture was stirredfor one hour at 0° and then for twenty hours at room temperature. Asmall amount of activated charcoal was then added to decompose anyexcess peracid, the mixture stirred for 30 minutes then filtered andconcentrated to give a viscous oil. The crude product was dissolved inwater, the pH adjusted to 9.0 with aqueous sodium bicarbonate and thematerial desalted by passage through a column of Sephadex G10. A whitesolid (20 mg;) was obtained after lyophylisation which wasspectroscopically essentially the same as the material obtained bymethod 1. ¹³C nmr (D₂O): δ 33.0, 38.7, 42.9, 43.0, 43.1, 53.9, 54.3,56.5, 61.6, 171.2, 176.4, 177.0.

EXAMPLE 3

Preparation of sodium sulfosuccinamic acid terminated dendrimers

A. PAMAM 1.0

Solid maleic anhydride (0.11 g; 1.1 mmol) was added to a stirredsolution of PAMAM 1.0 (0.12 g; 0.33 mmol) in dry DMF (3 ml). The mixturebecame a little warm and brownish as the anhydride dissolved and theresulting solution was stirred overnight at room temperature. Thesolution was then concentrated (30°/10⁻⁴ mmHg) to give a viscous oil. ¹Hand ¹³C nmr (D₂O) showed complete conversion of the PAMAM 1.0 to thetrisamide together with some maleic acid. ¹³C nmr (D₂O): δ 33.1, 42.8,43.1, 54.3, 135.0, 137.1, 169.1, 171.9, 173.3.

The crude trisamide was then dissolved in water (4 ml) and solid sodiumsulfite (0.20 g; 1.6 mmol) added. The resulting solution was allowed tostand at room temperature for four days and then concentrated. ¹H and¹³C nmr (D₂O) showed a 1:1 mixture of the regioisomeric sodiumsulfosuccinamic acid terminated PAMAM 1.0 dendrimers together with somesulfosuccinic acid. The crude product was purified by gel filtration(Sephadex G10; water) to afford a sample of the sodium sulfosuccinamicacid terminated PAMAM 1.0 dendrimers (107 mg). ¹³C nmr (D₂O): δ 33.3,39.6, 40.0, 42.9, 43.1, 54.0, 67.9, 69.4, 173.8, 176.3, 177.6, 181.8.

B. PAMAM 2.0

A mixture of the regioisomeric sodium sulfosuccinamic acid terminatedPAMAM 2.0 dendrimers was prepared as described above. ¹³C nmr PAMAM 2.0maleamic acid derivative (D₂O): δ 32.8, 33.0, 38.7, 42.9, 53.8, 54.3,56.5, 135.2, 136.8, 169.2, 171.9, 173.5, 174.6. ¹³C nmr PAMAM 2.0 sodiumsulfosuccinamic acid derivatives (D₂O): δ 37.0, 40.1, 41.1, 43.0, 43.2,43.9, 53.0, 53.3, 55.5, 68.0, 69.4, 173.8, 177.6, 179.1, 179.5, 179.8,182.3.

C. PAMAM 4.0 (Compound No. 14)

Solid maleic anhydride (60 mg; 0.6 mmol) was added to a stirred solutionof PAMAM 4.0 (51 mg; 0.01 mmol) in dry DMF (2 ml). The mixture initiallybecame cloudy but soon gave a clear solution which was stirred overnightat room temperature. The solution was then concentrated (35°/10⁻⁴ mmHg)to give a viscous oil. ¹H and ¹³C nmr (D₂O) showed complete conversionof the PAMAM 4.0 to the polyamide together with some maleic acid. Thecrude polyamide was then dissolved in water (2 ml) and a solution ofsodium sulfite (126 mg; 1.0 mmol) in water (2 ml) added. The resultingsolution was allowed to stand at room temperature for two days and thenconcentrated. ¹H and ¹³C nmr (D₂O) showed a mixture of the regioisomericsodium sulfosuccinamic acid terminated PAMAM 4.0 dendrimers togetherwith some sulfosuccinic acid. The crude product was purified by gelfiltration (Sephadex LH20; water) to afford a sample of PAMAM 4.0terminated with 24 regioisomeric sulfosuccinamic acid groups (90 mg). ¹Hnmr (D₂O): δ 2.4-2.6; 2.7-3.1; 3.2-3.4; 3.9-4.0. ¹³C nmr (D₂O): δ 36.2;39.8; 40.5; 43.0; 43.2; 53.5; 55.8; 68.1; 69.5; 173.8; 177.4; 177.6;178.7; 182.3.

EXAMPLE 4

Preparation of sodium N-(2-sulfoethyl)succinamide terminated dendrimers

a. Preparation of tetrabutylammonium N-(2-sulfoethyl)succinamic acid

Solid succinic anhydride (0.50 g; 5.0 mmol) was added to a stirredsolution of tetrabutylammonium 2-aminoethylsulfonic acid (1.83 g; 5.0mmol) in dry dichloromethane (30 ml). The succinic anhydride slowlydissolved and the resulting cloudy solution was stirred overnight atroom temperature. The mixture was filtered and the filtrate concentratedto give a viscous oil (2.41 g). ¹³C nmr showed complete conversion tothe desired monoamide together with a small amount of succinic acid.Repeated precipitation of the product by dropwise addition of adichloromethane solution to a large excess of diethyl ether gavetetrabutylammonium N-(2-sulfoethyl)succinamic acid as a white solid(1.762 g; 76% ), mp 125-127° C. 1 H nmr (CDCl₃): δ 0.86 (t, 12h, 4×CH₃),1.28 (m, 8H, 4×CH₂), 1.50 (m, 8H, 4×CH₂), 2.33 (m, 2H, CH₂COOH), 2.44(m, 2H, CH₂CONH), 2.76 (m, 2H, CH₂NHCO), 3.12 (m, 8H, 4×CH₂N), 3.50 (m,2H, CH₂SO₃ ⁻), 7.53 (br t, 1H, NH). ¹³C nmr (CDCl₃): δ 13.5, 19.5, 23.8,30.1, 30.9, 35.6, 50.0, 58.5, 172.0, 174.1.

b. Preparation of tetrabutylammonium 4-nitrophenylN-(2-sulfoethyl)-succinamate

A solution of dicyclohexylcarbodiimide (45 mg; 0.22 mmol) in drydichloromethane (1 ml) was added to a stirred solution oftetrabutylammonium N-(2-sulfoethyl)succinamic acid (94 mg; 0.20 mmol)and 4-nitrophenol (28 mg; 0.20 mmol) in dichloromethane (2 ml), and themixture stirred overnight at room temperature. The resulting suspensionwas filtered and the filtrate concentrated to give the crude activeester, which was used without further purification.

A. Preparation of sodium N-(2-sulfoethyl)succinamide terminated PAMAMdendrimers

PAMAM 4.0

A solution of the crude tetrabutylammonium 4-nitrophenylN-(2-sulfoethyl)succinamate (0.30 mmol) in dry DMF (1 ml) was added to astirred solution of PAMAM 4.0 (51.5 mg; 0.01 mmol) dissolved in 50%aqueous DMF (3 ml) and the resulting yellow solution stirred overnightat room temperature. The mixture was then concentrated (35°/10⁻⁵ mmHg)and the yellow residue partitioned between water and chloroform. Thewater layer was separated, washed with chloroform (2×) and ethylacetate, and then concentrated to give a yellow oil (134 mg). The crudeproduct was converted to the sodium salt by passage through a column ofAmberlite IR-120(Na) to yield 85 mg of material. This material wasfurther purified by gel filtration (Sephadex LH20; water) to give thesodium N-(2-sulfoethyl)succinamide terminated PAMAM 4.0 dendrimer (45mg). ¹³C nmr (D₂O): δ 33.2, 33.6, 35.5, 39.0, 39.5, 42.8, 43.2, 53.8,54.1, 54.4, 56.6, 176.5, 176.9, 177.2, 178.9, 179.4.

The corresponding PAMAM 1.0 and PAMAM 3.0 dendrimers terminated withsodium N-(2-sulfoethyl)succinamide groups were similarly prepared. ¹³Cnmr PAMAM 3.0 derivative (D₂O): δ 33.4, 35.5, 39.0, 39.5, 42.9, 43.2,53.8, 54.1, 54.3, 56.5, 176.4, 176.9, 177.4, 178.9, 179.4.

¹³C nmr PAMAM 1.0 derivative (D₂O): δ 34.9, 35.5, 39.5, 42.9, 43.1,53.7, 54.1, 179.0, 179.1, 179.3.

B. Preparation of sodium N-(2-sulfoethyl)succinamide terminatedpolylysine dendrimers.

BHAlyslys₂lys₄lys₈lys₁₆

Trifluoroacetic acid (1 ml) was added to a suspension ofBHAlyslys₂lys₄lys₈DBL₁₆ (36.5 mg; 5.0 μmol) in dry dichloromethane (1ml) and the resulting solution stirred at room temperature undernitrogen for two hours and then concentrated. The residue was dissolvedin dry DMSO (2 ml) and the pH adjusted to 8.5 with triethylamine. Asolution of the crude tetrabutylammonium 4-nitrophenylN-(2-sulfoethyl)succinamate (ca. 0.2 mmol) in DMSO (1 ml) was then addeddropwise and the mixture stirred overnight at room temperature. Theyellow solution was then concentrated (50°/10⁻⁵ mmHg) and the yellowresidue partitioned between water and chloroform. The aqueous layer wasseparated, washed with chloroform (3×) and ethyl acetate, and thenconcentrated to give an oil (99 mg). The crude product was converted tothe sodium salt by passage through a column of Amberlite IR 120(Na) toyield 81 mg of material. This material was further purified by gelfiltration (Sephadex LH20; water) to give the sodiumN-(2-sulfoethyl)succinamide terminatedBHAlyslys₂lys₄lys₈lys₁₆dendrimer(39 mg). ¹³C nmr (D₂O): δ 27.0, 32.3,35.2, 35.3, 35.6, 35.7, 39.5, 43.5, 54.1, 58.5, 131.5, 132.0, 133.3,145.1, 177.8, 178.0, 178.4, 178.8, 178.9, 179.2, 179.7, 179.8.

The corresponding BHAlyslys₂BHAlyslys₂lys₄ and BHAlyslys₂lys₄lys₈terminated with sodium N-(2-sulfoethyl)succinamide groups were similarlyprepared. ¹³C nmr BHAlyslys₂lys₄lys₈ derivative (D₂O): δ 26.9, 32.3,35.1, 35.3, 35.6, 35.7, 39.5, 43.5, 54.1, 58.5, 131.6, 131.9, 132.2,132.3, 133.2, 133.3, 145.0, 145.2, 177.2, 177.8, 177.9, 178.0, 178.2,178.3, 178.6, 178.7, 178.8, 178.9, 179.2, 179.3, 179.7, 179.8.

¹³C nmr BHAlyslys₂lys₄ derivative (D₂O): δ 26.9, 32.3, 35.1, 35.4, 35.7,35.8, 39.5, 43.5, 54.1, 58.5, 61.8, 131.7, 132.0, 132.2, 132.3, 133.2,133.3, 145.0, 145.1, 177.3, 178.0, 178.3, 178.4, 178.7, 178.9, 179.0,179.3, 179.7, 179.8.

¹³C nmr BHAlyslys₂ derivative (D₂O): δ 26.9, 27.1, 32.2, 32.3, 34.7,34.8, 35.1, 35.3, 35.6, 35.7, 39.5, 43.4, 54.1, 58.6, 61.8, 131.7,131.9, 132.2, 132.3, 133.3, 144.9, 145.0, 177.7, 178.4, 178.8, 179.0,179.3, 180.0.

EXAMPLE 5

Preparation of sodium 4-sulfophenylthiourea terminated dendrimers

A. PAMAM 4.0 (Compound No. 1)

Solid sodium 4-sulfophenylisothiocyanate monohydrate (500 mg; 1.96 mmol)was added to a solution of PAMAM 4.0 (300 mg; 0.0582 mmol) in water (10ml) and the resulting solution heated under nitrogen at 53° for twohours and then cooled. The solution was concentrated and the yellowsolid residue purified by gel filtration (Sephadex LH20; water). Thepure fractions were combined and freeze dried to give the sodium4-sulfophenylthiourea terminated PAMAM 4.0 dendrimer as a fluffy whitesolid (370 mg). ¹H nmr (D₂O): δ 2.28; 2.52; 2.69; 3.15; 3.27; 3.60; 7.32(d, J=9 Hz); 7.72 (d, J=9 Hz). ¹³C nmr (D₂O): δ 36.9; 41.1; 43.1; 48.3;53.6; 55.8; 129.0; 131.1; 144.4; 178.5; 179.1; 184.4.

The corresponding PAMAM 1.0 and PAMAM 2.0, PAMAM 3.0 and PAMAM 5.0(Compound No. 2) dendrimers terminated with 3, 6, 12 and 48 sodium4-sulfophenylthiourea groups respectively were similarly prepared.

B. PAMAM 4.0 (EDA) (Compound No. 3)

Solid sodium 4-sulfophenylisothiocyanate monohydrate (130 mg; 0.5 mmol)was added to a solution of PAMAM 4.0 (EDA) (69 mg; 0.01 mmol) in water(4 ml) and the resulting solution heated under nitrogen at 53° for twohours and then cooled. The solution was concentrated and the solidresidue purified by gel filtration (Sephadex LH20; water). The purefractions were combined and freeze dried to give PAMAM 4.0 terminatedwith 32 sodium 4-sulfophenylthiourea groups as a fluffy white solid (136mg). ¹H nmr (D₂O): δ 2.30; 2.50; 2.70; 3.18; 3.62; 7.35 (d, J=9 Hz);7.72 (d, J=9 Hz). ¹³C nmr (D₂O): δ 36.8; 41.0; 43.1; 48.4; 53.6; 55.7;128.9; 131.0; 144.3; 178.5; 179.0; 184.5.

C. BHAlyslys₂lys₄lys₈lys₁₆ (Compound No. 4)

Trifluoroacetic acid (4 ml) was added to a suspension ofBHAlyslys₂lys₄lys₈DBL₁₆ (0.73 g; 0.1 mmol) in dry dichloromethane (4 ml)under nitrogen. A vigorous evolution of gas was observed for a shorttime and the resulting solution was stirred at room temperature for twohours and then concentrated. The residual syrup was dissolved in water(5 ml), the solution passed through a column of Amberlite IRA-401(OH)and the filtrate concentrated to give BHAlyslys₂lys₄lys₈lys₁₆ as aviscous oil (0.49 g). The oil was redissolved in water (5 ml) andN,N-dimethyl-N-allylamine buffer (pH 9.5; 3 ml) added. Solid sodium4-sulfophenylisothiocyanate monohydrate (1.30 g; 5.1 mmol) was thenadded and the resulting solution heated under nitrogen at 53° for twohours and then cooled. The solution was concentrated and the brownishsolid residue purified by gel filtration (Sephadex LH20; water). Thepure fractions were combined, passed through a column of Amberlite IR120(Na) and freeze dried to give the sodium 4-sulfophenylthioureaterminated BHAlyslys₂lys₄lys₈lys₁₆ dendrimer as a fluffy white solid(374 mg). ¹H nmr (D₂O): δ 1.40; 1.72; 3.08; 3.42; 4.24; 4.60; 7.30; 7.40(d, J=9 Hz); 7.78 (d, J=9 Hz). ¹³C nmr (D₂O): δ 27.3; 32.5; 35.9; 43.7;48.9; 58.6; 63.3; 128.8; 131.0; 143.7; 144.7; 145.1; 177.7; 178.1;183.8; 185.2.

The corresponding BHAlyslys₂lys₄lys₈, BHAlyslys₂lys₄lys₈lys₁₆lys₃₂(Compound No. 5), and BHAlyslys₂lys₄lys₈lys₁₆lys₃₂lys₆₄ (Compound No. 6)dendrimers terminated with 16, 64, and 128 sodium 4-sulfophenylthioureagroups respectively were similarly prepared.

EXAMPLE 6

Preparation of sodium 3,6-disulfonapthylthiourea terminated dendrimers

A. PAMAM 4.0 (Compound No. 9)

Solid sodium 3,6-disulfonapthylisothiocyanate (160 mg; 0.41 mmol) wasadded to a solution of PAMAM 4.0 (51 mg; 0.01 mmol) in water (3 ml) andthe resulting solution heated under nitrogen at 53° for two hours andthen cooled. The solution was concentrated and the brown solid residuepurified by gel filtration (Sephadex LH20; water). The pure fractionswere combined and concentrated to give the sodium3,6-disulfonapthylthiourea terminated PAMAM 4.0 dendrimer as a brownishsolid (73 mg). ¹H nmr (D₂O): δ 2.30; 2.60; 2.74; 3.20; 3.57; 7.75; 7.86;8.28. ¹³C nmr (D₂O): δ 35.0; 39.9; 43.1; 48.1; 53.8; 56.1; 128.4; 128.6;129.3; 131.0; 131.3; 136.0; 136.8; 138.2; 145.5; 146.0; 177.2; 177.8;185.5.

The corresponding PAMAM 2.0 dendrimer terminated with sodium3,6-disulfonapthylthiourea groups was similarly prepared.

B. PAMAM 4.0 (EDA) (Compound No. 11)

Solid sodium 3,6-disulfonapthylisothiocyanate (220 mg; 0.57 mmol) wasadded to a solution of PAMAM 4.0 (EDA) (74 mg; 0.01 mmol) in water (4ml) and the resulting solution heated under nitrogen at 53° for twohours and then cooled. The solution was concentrated and the brownishsolid residue purified by gel filtration (Sephadex LH20; water). Thepure fractions were combined and concentrated to give PAMAM 4.0terminated with 32 sodium 3,6-disulfonapthylthiourea groups as a tansolid (148 mg). ¹H nmr (D₂O): δ 2.30; 2.80; 3.20; 3.54; 7.74; 7.85;8.25. ¹³C nmr (D₂O): δ 36.0; 40.8; 43.1; 48.3; 53.6; 5.9; 128.5; 129.4;131.0; 131.3; 136.0; 136.8; 138.3; 145.5; 146.0; 178.2; 185.6.

C. BHAlyslys₂lys₄lys₈lys₁₆ (Compound No. 12)

Trifluoroacetic acid (2 ml) was added to a suspension ofBHAlyslys₂lys₄lys₈DBL₁₆ (73 mg; 0.01 mmol) in dry dichloromethane (2 ml)under nitrogen A vigorous evolution of gas was observed for a short timeand the resulting solution was stirred at room temperature for two hoursand then concentrated. The residual syrup was dissolved in water (5 ml),the solution passed through a column of Amberlite IRA-401 (OH) and thefiltrate concentrated to give BHAlyslys₂lys₄lys₈lys₁₆ as a viscous oil.The oil was redissolved in water (5 ml) and N,N-dimethyl-N-allylaminebuffer (pH 9.5; 3 ml) added. Solid sodium3,6-disulfonapthylisothiocyanate (234 mg; 0.60 mmol) was then added andthe resulting solution heated under nitrogen at 53° for two hours andthen cooled. The solution was concentrated and the brownish solidresidue purified by gel filtration (Sephadex LH20; water). The purefractions were combined, passed through a column of Amberlite IR 120(Na)and freeze dried to give BHAlyslys₂lys₄lys₈lys₁₆ terminated with 32sodium 3,6-disulfonapthylthiourea groups as a fluffy off-white solid(119 mg). ¹H nmr (D₂O): δ 1.0-2.0; 3.18; 3.43; 4.31; 7.22; 7.80; 7.89;8.25. ¹³C nmr (D₂O): δ 27.2; 32.4; 35.3; 43.7; 49.0; 58.5; 63.6; 128.4;129.1; 131.4; 136.1; 136.6; 138.6; 139.0; 145.1; 145.6; 178.4; 184.8;186.7.

EXAMPLE 7

Preparation of sodium 4-sulfonapthylthiourea terminated dendrimers

PAMAM 4.0 (Compound No. 8)

Solid sodium 4-sulfonapthylisothiocyanate (180 mg; 0.5 mmol) was addedto a solution of PAMAM 4.0 (51 mg; 0.01 mmol) in water (5 ml) and themixture heated under nitrogen at 530 for two hours and then cooled. Thewater was distilled under reduced pressure from the resulting suspensionand the off white solid residue purified by gel filtration (SephadexLH20; water). The pure fractions were combined and freeze dried to givethe sodium 4-sulfonapthylthiourea terminated PAMAM 4.0 dendrimer as afluffy white solid (60 mg). ¹H nmr (D₂O): δ 2.20; 2.60; 3.14; 3.48;7.23; 7.47; 7.56; 7.77; 7.93 (d, J=6 Hz); 8.56 (d, J=6 Hz). ¹³C nmr(D₂O): δ 35.8; 40.5; 43.1; 48.4; 53.6; 55.9; 127.6; 128.6; 130.3; 131.9;132.5; 133.5; 134.7; 140.5; 142.7; 177.8; 178.0; 185.4.

EXAMPLE 8

Preparation of sodium 3,5-disulfophenylthiourea terminated dendrimers

PAMAM 4.0 (Compound No. 7)

Solid sodium 3,5-disulfophenylisothiocyanate (110 mg; 0.32 mmol) wasadded to a solution of PAMAM 4.0 (63 mg; 0.012 mmol) in water (3 ml) andthe resulting solution heated under nitrogen at 53° for two hours andthen cooled. The solution was concentrated and the brownish solidresidue purified by gel filtration (Sephadex G25; water). The purefractions were combined and concentrated to give PAMAM 4.0 terminatedwith 24 sodium 3,5-disulfophenylthiourea groups as an off-white solid(110 mg). ¹H nmr (D₂O): δ 2.53; 3.08; 3.36; 3.66; 7.90; 7.95. ¹³C nmr(D₂O): δ 34.8; 41.0; 43.1; 48.0; 53.7; 56.2; 124.1; 128.6; 143.5; 148.8;177.6; 185.0.

EXAMPLE 9

Preparation of sodium 3, 6, 8-trisulfonaphthylthiourea terminateddendrimers

PAMAM 4.0 (Compound No. 10)

Solid sodium 3, 6, 8-trisulfonaphthylisothiocyanate (250 mg; 0.5 mmol)was added to a solution of PAMAM 4.0 (51 mg; 0.01 mmol) andN,N-dimethyl-N-allylamine buffer (pH 9.5; 1 ml) in water (2 ml) and themixture heated under nitrogen at 53° for two hours and then cooled. Themixture was concentrated under reduced pressure to give an orange solid.The residual solid was dissolved in water (2 ml) and passed through ashort column of Amberlite IR-120(Na). The filtrate was then concentratedand the residue purified by gel filtration (Sephadex LH20; water). Thepure fractions were combined and freeze dried to give the sodium 3, 6,8-trisulfonaphthylthiourea terminated PAMAM 4.0 dendrimer as anoff-white solid (102 mg). ¹H nmr (D₂O): δ 2.65; 3.02; 3.30; 3.66; 8.05;8.42; 8.59; 8.67. ¹³ C nmr (D₂O): δ 33.2; 38.7; 43.2; 43.7; 47.8; 54.0;54.3; 56.7; 131.0; 131.3; 131.9; 135.9; 138.0; 139.6; 143.8; 144.1;145.6; 176.2; 176.5; 186.0.

EXAMPLE 10

Preparation of sodium 4-(sulfomethyl)benzamide terminated dendrimers

PAMAM 4.0 (Compound No. 13)

Solid 4-nitrophenyl 4-(chloromethyl)benzoate (200 mg; 0.68 mmol) wasadded to a stirred solution of PAMAM 4.0 (70 mg; 0.014 mmol) in dry DMSO(4 ml) and the resulting yellow solution stirred at room temperature fortwo hours. The solution was then concentrated (10⁻⁴ mmHg; 40°) and theresidue extracted with a mixture of water and dichloromethane (1:1). Theremaining solid material was dissolved in DMSO (5 ml) and a solution ofsodium sulfite (130 mg; 1 mmol) in water (3 ml) added. The slightlycloudy mixture that resulted was left to stand for four days, afterwhich time the addition of more water (2 ml) resulted in the formationof a clear homogeneous yellow solution. The solution was thenconcentrated, first at 25 mmHg and 40 then at 10 mmHg and 50 to give thecrude product. The crude product was purified by gel filtration(Sephadex G25; water) to give PAMAM 4.0 terminated with 24 sodium4-(sulfomethyl)benzamide groups (24 mg). ¹H nmr (D₂O): δ 2.25; 2.66;3.08; 3.20; 3.33; 3.38; 4.01; 7.40 (br d); 7.62 (br d). ¹³C nmr (D₂O): δ36.7; 40.9; 43.0; 43.6; 53.5; 55.5; 61.0; 131.6; 135.0; 137.2; 140.4;174.5; 178.6; 179.2.

EXAMPLE 11

Preparation of 4-sulfobenzamide terminated dendrimers

PAMAM 4.0 (EDA)

Solid potassium N-hydroxysuccinimidyl 4-sulfobenzoate (100 mg; 0.3 mmol)was added to a solution of PAMAM 4.0 (EDA) (35 mg; 0.005 mmol) in 0.1 MpH 8.5 borate buffer (5 ml) and the solution stirred at room temperaturefor two hours. The resulting milky solution at this stage had a pH of4.5. 1M Sodium carbonate solution (1 ml) was then added to give a clearsolution which was concentrated to give the crude product as a whitesolid. The crude product was purified by gel filtration (Sephadex G25;water) to give PAMAM 4.0 EDA) terminated with 32 sodium 4-sulfobenzamidegroups (47 mg). ¹H nmr (D₂O) δ 2.25; 2.42; 2.63; 3.05; 3.18; 3.31; 3.38;7.72 (d, s=8 Hz); 7.78 (d, 3=8 Hz). ¹³C nmr (D₂O): δ 36.0; 40.4; 43.0;43.7; 53.7; 55.8; 130.2; 132.2; 140.4; 150.1; 173.6; 178.0; 178.5.

EXAMPLE 12

Preparation of Sodium N-(4-sulfophenyl)propanamide terminated dendrimers

PAMAM 4.0 (EDA)

Solid sodium N-(4-sulfophenyl)acrylamide (250 mg; 1 mmol) and solidsodium carbonate (106 mg; 1 mmol) were added successively to a stirredsolution of PAMAM 4.0 (EDA) (78 mg; 0.011 mmol) in water (4 ml). Theresulting solution was stirred under nitrogen for four days and thenfreeze dried to give a fluffy white solid. The crude product waspurified by gel filtration (Sephadex LH20; water to give PAMAM 4.0 (EDA)terminated with 64 sodium N-(4-sulfophenyl)propanamide groups (206 mg).¹³C nmr showed a faint trace of what was taken to be mono alkylatedterminal amino groups. ¹H nmr (D₂O):δ 2.10; 2.48; 2.58; 2.79; 3.20; 7.42(d, J=7 Hz); 7.65 (d, J=7 Hz). ¹³C nmr (D₂O): δ 36.5; 37.9; 41.1; 53.4;55.6; 124.8; 130.9; 143.0; 144.2; 177.4; 178.5.

EXAMPLE 13

Preparation of Sodium 4-sulfophenylurea terminated dendrimers

PAMAM 4.0 (EDA)

A solution of sodium sulfanilic acid (195 mg; 1 mmol) in dry DMSO (3 ml)was added dropwise to a solution of N,N′-disuccinimidyl carbonate (530mg; 2 mmol) in dry DMSO (4 ml) and the resulting brownish solutionstirred at room temperature for 20 hours. A solution of PAMAM 4.0 (EDA)(75 mg; 0.011 mmol) in dry DMSO (1 ml) added and the solution stirredfor a further 18 hours. The solution was then concentrated under highvacuum (10⁻⁵ mmHg; 35°) to give a yellowish semi solid. The crudeproduct was dissolved in DMSO (4 ml) and the solution added to 200 ml ofwell stirred ethyl acetate. The precipitated white solid was collectedby filtration and washed with ethyl acetate (2×) and ether (2×), thendried to give a white powder (275 mg). This material was furtherpurified by gel filtration (Sephadex LH20; water) to give PAMAM 4.0(EDA) terminated with 32 sodium 4-sulfophenylurea groups (106 mg). ¹Hnmr (D₂O): 62.31; 2.55; 2.75; 3.19; 7.32 (d, J=9 Hz); 7.63 (d, J=9 Hz).¹³C nmr (D₂O): δ 36.3; 40.7; 43.3; 43.8; 53.7; 55.7; 123.3; 130.9;140.9; 146.0; 161.4; 178.2; 178.6.

EXAMPLE 14

Preparation of N,N,N-trimethylglycinamide chloride terminateddendrimers.

BHAlyslys₂lys₄lys₈lys₁₆ (Compound No. 15)

Trifluoroacetic acid (4 ml) was added to a suspension ofBHAlyslys₂lys₄lys₈DBL₁₆ (220 mg; 30 μmol) in dry dichloromethane (2 ml)and the resulting solution stirred at room temperature under nitrogenfor two hours and then concentrated. The residue was dissolved in dryDMSO (5 ml) and the pH adjusted to 8.5 with triethylamine. Solid4-nitrophenyl N,N,N-trimethylglycinate chloride (0.50 g; 1.8 mmol) wasthen added and the mixture stirred overnight at room temperature. Thecloudy solution was then concentrated (50°/10⁻⁵ mmHg) and the residuepartitioned between water and dichloromethane. The aqueous layer wasseparated, washed with dichloromethane (3×) and ethyl acetate, and thenconcentrated to give an oil (1.128 g). The crude product was purified bygel filtration (Sephadex LH20; water) to give theN,N,N-trimethylglycinamide terminated BHAlyslys₂lys₄lys₈lys₁₆ dendrimer(116 mg). ¹³C nmr (D₂O): δ 25.5, 30.5, 30.8, 33.4, 42.1, 56.5, 57.1,67.5, 68.1, 166.7, 167.0, 167.1, 176.0, 176.2.

EXAMPLE 15

Preparation of 4-Trimethylammoniumbenzamide terminated dendrimers

PAMAM 4.0 (Compound No. 16)

1,1′-Carbonyldiimidazole (85 mg; 0.52 mmol) was added to a solution of4-trimethylammoniumbenzoic acid iodide (154 mg; 0.5 mmol) in dry DMF (4ml) and the mixture stirred at room temperature under argon for twohours. During this time a white solid separated from the solution. Asolution of PAMAM 4.0 (58 mg; 0.011 mmol) in dry DMF (2 ml) was thenadded and the mixture stirred overnight at room temperature. After thistime most of the precipitate had dissolved and a ninhydrin test of thesolution was negative. The mixture was concentrated (10 mmHg; 30°) togive a white solid residue. The crude product was purified by gelfiltration (Sephadex LH20; 10% AcOH) to give PAMAM 4.0 terminated with24 4-trimethylammoniumbenzamide groups as the acetic acid salt (89 mg).¹H nmr (D₂O): δ 1.96; 2.65-2.85; 3.25-3.55; 3.64; 7.92. ¹³C nmr (D₂O): δ25.8; 33.1; 33.5; 38.7; 43.1; 43.5; 53.5; 54.1; 56.4; 61.2; 124.8;133.6; 139.9; 153.2; 173.2; 176.3; 176.8; 182.6.

The corresponding PAMAM 2.0 dendrimer terminated with 64-trimethylammonium benzamide groups was similarly prepared.

EXAMPLE 16

Preparation of 4-(Trimethylammoniummethyl)benzamide terminateddendrimers

PAMAM 4.0 (Compound No. 17)

Solid 4-nitrophenyl 4-(chloromethyl)benzoate (150 mg; 0.5 mmol) wasadded to a stirred solution of PAMAM 4.0 (52 mg; 0.01 mmol) in dry DMSO(3 ml). The resulting yellow solution was stirred at room temperaturefor 20 hours, when a ninhydrin test was negative (pH ca.8.5). Thesolution was then concentrated (10 mmHg; 40 ) and the residue shakenwith a mixture of water and dichloromethane (1:1). The insolublegel-like material was collected by filtration, washed with water (2×)and dichloromethane (2×), and then air dried. The crude4-(chloromethyl)benzamide terminated dendrimer was dissolved in 25% aq.trimethylamine (20 ml) and the yellow solution left to stand overnight.The solution was then concentrated, the residue dissolved in water (5ml) and the solution passed through a column of Amberlite IRA-401 (OH).The colourless filtrate was concentrated to give a viscous oil which waspurified by gel filtration (Sephadex G10; 10% AcOH) to give PAMAM 4.0terminated with 24 4-(trimethylammoniummethyl)benzamide groups (90 mg).¹H nmr (D₂O): δ 1.88; 2.65-2.80; 2.98; 3.10-3.60; 7.52 (br d, J=9 Hz);7.72 (br d, J=9 Hz). ¹³C nmr (D₂O): δ 26.6; 33.4; 38.8; 43.2; 43.5;53.6; 53.6; 54.1; 56.8; 62.8; 73.0; 132.1; 135.3; 137.5; 140.0; 176.4;176.9; 183.6.

EXAMPLE 17

Preparation ofN-(2-Acetoxyethyl)-N,N-(dimethylammonium)methylcarboxamide terminateddendrimers

PAMAM 4.0

Solid 1,1′-carbonyldiimidazole (85 mg; 0.52 mmol) was added to asolution of N-(2-acetoxyethyl)-N-(carboxymethyl)-N,N-dimethylammoniumbromide (135 mg; 0.5 mmol) in dry DMF (3 ml) and the resulting solutionstirred under nitrogen for two hours. A solution of PAMAM 4.0 (60 mg;0.012 mmol) in DMF (2 ml) was then added, which caused the immediateformation of a flocculant precipitate which slowly redissolved. Themixture was stirred for two days and then concentrated (10⁻⁴ mmHg; 40°)to give a viscous oil. The crude product was purified by gel filtration(Sephadex G10; 10% AcOH) to give PAMAM 4.0 terminated with 24N-(2-Acetoxyethyl)-N,N-(dimethylammonium)methylcarboxamide groups (64mg). ¹H nmr (D₂O): δ 1.93; 2.05; 2.70; 3.10-3.60; 3.28; 3.93 (m); 4.14;4.48 (m). ¹³C nmr (D₂O): δ 24.6; 26.2; 33.2; 38.7; 42.8; 42.9; 53.9;57.4; 62.6; 67.3; 67.5; 168.9; 176.4; 176.8; 177.3; 183.2.

EXAMPLE 18

Preparation of Guanidino terminated dendrimers

PAMAM 4.0 (Compound No. 18)

A solution of PAMAM 4.0 (63 mg; 0.012 mmol) and methylthiopseudoureasulfate (170 mg; 0.61 mmol) in water (5 ml) (pH 10.5) was heated undernitrogen at 80° for two hours. The solution was then concentrated andthe residue purified by gel filtration (Sephadex G10; 10% AcOH) to givePAMAM 4.0 terminated with 24 guanidino groups as the acetate salt (107mg). ¹H nmr (D₂O): δ 2.00; 2.80 (br t); 3.09 (br t); 3.32; 3.45 (br t);3.60 (br t). ¹³C nmr (D₂O): δ 25.2; 33.2; 33.4; 38.7; 41.2; 42.6; 43.4;44.7; 53.5; 54.0; 56.3; 176.5; 176.7; 176.9; 181.6.

The corresponding PAMAM 2.0 dendrimer terminated with 6 guanidino groupswas similarly prepared.

EXAMPLE 19

Preparation of 4-([1,4,8,11-tetraazacyclotetradecane]methyl)benzamideterminated dendrimers

PAMAM 4.0 (Compound No. 19)

A solution of 1-(4-carboxyphenyl)methyl-1,4,8,11-tetraaacyclotetradecane tetra hydrochloride (120 mg; 0.25 mmol),N-hydroxysuccinimide (60 mg; 0.52 mmol) and1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (250 mg; 1.3mmol) in pH 7 phosphate buffer (10 ml) was allowed to stand a roomtemperature for one hour and then a solution of PAMAM 4.0 (32 mg; 0.006mmol) in pH 7 phosphate buffer (10 ml) added. The mixture was allowed tostand for two days and then concentrated. The residue was purified bygel filtration (Sephadex LH20; 10% AcOH) to give PAMAM 4.0 terminatedwith ca 12 4-([1,4,8,11-tetraaaacyclotetradecane]methyl)benzamide groupsas determined by ¹H and ¹³C nmr (80 mg). The product was then dissolvedin water and passed through a column of Amberlite IRA-401 (Cl) resin andthen concentrated. The residue was dissolved in water (1 ml),concentrated HCl (1 ml) added, and the solution diluted with ethanol (30ml) to precipitate a white solid. The solid was collected by filtration(68 mg). Once again ¹H and ¹³C nmr showed ca. 50% functionalisation ofthe terminal amino groups. ¹H nmr (D₂O): δ 2.17; 2.36; 2.50; 2.78; 2.85;3.25; 3.40; 3.50; 3.60; 3.62; 4.49; 7.63 (br d); 7.78 (br d). ¹³C nmr(D₂O): δ 22.7; 23.1; 33.2; 38.8; 39.9; 40.2; 40.3; 41.0; 41.2; 42.0;42.9; 43.2; 43.6; 45.5; 46.1; 49.1; 52.2; 53.9; 54.3; 56.6; 62.7; 132.5;135.7; 137.1; 139.7; 174.3; 176.2; 176.3; 176.7; 177.0; 178.2; 178.5.

EXAMPLE 20

Preparation of 4-Carboxy-3-hydroxybenzylamine terminated dendrimers

PAMAM 4.0 (EDA)

Sodium cyanoborohydride (32 mg; 0.5 mmol) was added to a mixture ofPAMAM 4.0 (EDA) (69 mg; 0.01 mmol), 4-formyl-2-hydroxybenzoic acid (83mg; 0.5 mmol), and sodium hydrogen carbonate (42 mg; 0.5 mmol) in water(4 ml). The inhomogeneous orange mixture was stirred for four hours atroom temperature, during which time it became homogeneous. The orangesolution was then concentrated and the residue purified by gelfiltration (Sephadex LH20; water) to give PAMAM 4.0 (EDA) terminatedwith ca. 32 4-carboxy-3-hydroxybenzylamine groups (91 mg). ¹H and ¹³Cnmr (D₂O) shows mostly mono alkylation but with some signs ofdialkylation of the terminal amino groups, both spectra show broadpeaks. ¹³C nmr (D₂O):δ 37.0; 41.1; 50.9; 53.4; 55.5; 55.8; 61.5; 120.9;122.2; 122.4; 132.3; 132.7; 135.0; 135.8; 163.5; 163.7; 169.0; 178.6;179.3. ¹H nmr (D₂O): δ 2.20; 2.35; 2.60; 3.15; 3.30; 3.55; 4.25; 6.68;7.12; 7.55.

EXAMPLE 21

Test for anticoagulant activity

Bovine blood was collected from the abattoir, where an animal was bledinto a bucket containing sodium citrate at a concentration of 3.5 g perliter of fresh blood. This blood was returned to the laboratory where itwas kept in a 37° C. water bath.

Aliquots of the whole blood were then centrifuged at 3000 rpm for 5minutes to separate the plasma This was collected and returned to thewater bath. Extra plasma was also prepared and stored in liquid nitrogenfor later testing.

The procedure actually tests the recalcification time of the citratedblood at 37° C. All glassware was washed, dried and silated with‘Coatasil’ before re-washing and drying. Each 12×75 mm culture tubecontained 0.1 ml of plasma, 0.1 ml of saline solution (0.9% NaCl)followed by 0.1 ml of 0.025M CaCl₂ at which time the stop watch wasstarted. Every 15 sec the tube was tilted to one side and clotting wasassessed. When a firm clot had formed, the watch was stopped and thetime recorded. In the case of testing anti-coagulants 0.1 ml of the testsubstance replaced the saline. The times for a range of concentrationsfor the test compounds are recorded in Table 1. Heparin, sodium citrateand test compound were made up in water as 10 mg/ml solutions. Thesesolutions were diluted to give a range of concentrations. The finalconcentrations in the test tubes are given in the table. The figures inthe table represent average times for, up to ten replicates.

TABLE 1 Time for plasma coagulation at 37° C. for followingconcentrations of anticoagulant Con- 0.0003 0.003 0.03 0.33 3.33Compound trols mg/ml mg/ml mg/ml mg/ml mg/ml Heparin 2.292.30 >30 >30 >30 — min min min min min Sodium 2.29 — — 2.30 2.30 >30citrate min min min min Compound 2.11 — — 2.29 4.00 >30 No. 1 min minmin min Compound 2.08 — — 1.72 10.00 >30 No. 4 min min min* min Compound2.20 — 2.34 7 8 — No. 15 min min min* min* Compound 2.27 — 2.19 4 5.40 —No. 9 min min min min*

EXAMPLE 23

Test for antiviral activity.

The results of tests of activity against HIV1, HIV2, CMV and variousherpes simplex viruses (HSV) are recorded in Tables 2 to 5,respectively.

TABLE 2 HIV 1 Activity Results Antiviral Dendrimer Terminal Group EC₅₀μM CC₅₀ μM Index (1) PAMAM 4.0 24 end groups

0.0492 >125 >2543 (2) PAMAM 5.0 48 end groups

0.0096 >11 >1180 (3) PAMAM 4.0 (EDA) 32 end groups

0.0142 >17.2 >1212 (4) BHAlys₁₅lys₁₆ 32 end groups

0.0126 100.91 7991 (5) BHAlys₃₁lys₃₂ 64 end groups

0.0332 >10 >320 (6) BHAlys₆₃lys₆₄ 128 end groups

0.0530 >5 >100 (7) PAMAM 4.0 24 end groups

0.003 >18.8 >9091 (8) PAMAM 4.0 24 end groups

0.0694 >20 >300 (9) PAMAM 4.0 24 end groups

0.0032 >125 >39000 (10) PAMAM 4.0 24 end groups

0.0041 >14 >3500 (11) PAMAM 4.0 (EDA) 32 end groups

0.0051 >12.9 >2537 (12) BHAlys₁₅lys₁₆ 32 end groups

0.0088 >15 >1700 (13) PAMAM 4.0 24 end groups

0.0088 >24 >2737 (14) PAMAM 4.0 24 end groups

0.2849 >25 >88 (15) BHAlys₁₅lys₁₆ 32 end groups

0.0725 >125 >1720 (16) PAMAM 4.0 24 end groups

1.2559 >25 >20 (17) PAMAM 4.0 24 end groups

0.2973 2.3406 8 (18) PAMAM 4.0 24 end groups

0.2739 3.4983 13 (19) PAMAM 4.0 ca. 12 end groups

0.0538 3.2183 60

TABLE 3 HIV 2 Activity Results Antiviral Dendrimer Terminal Group EC₅₀μM CC₅₀ μM Index (1) PAMAM 4.0 24 end groups

0.2237 >125 >560 (2) PAMAM 5.0 48 end groups

0.1490 >11 >76 (3) PAMAM 4.0 (EDA) 32 end groups

0.2368 >17.2 >73 (4) BHAlys₁₅lys₁₆ 32 end groups

0.1130 108.0417 956 (5) BHAlys₃₁lys₃₂ 64 end groups

0.2063 >10 >52 (6) BHAlys₆₃lys₆₄ 128 end groups

0.2227 >5 >24 (7) PAMAM 4.0 24 end groups

0.24 >18.8 >77 (8) PAMAM 4.0 24 end groups

0.4913 >20 >42 (9) PAMAM 4.0 24 end groups

0.0674 >125 >1854 (10) PAMAM 4.0 24 end groups

0.0299 >14 >493 (11) PAMAM 4.0 (EDA) 32 end groups

0.0234 >12.9 >551 (12) BHAlys₁₅lys₁₆ 32 end groups

0.1778 >15 >85 (13) PAMAM 4.0 24 end groups

0.1080 >24 >222 (14) PAMAM 4.0 24 end groups

6.002 >25 >4 (15) BHAlys₁₅lys₁₆ 32 end groups

>125 >125 (16) PAMAM 4.0 24 end groups

>25 >25 (17) PANAM 4.0 24 end groups

>7.175 >7.175 <1 (18) PAMAM 4.0 24 end groups

>10.817 10.817 <1 (19) PAMAM 4.0 ca. 12 end groups

0.2175 2.4245 11

TABLE 4 Activity against Human Cytomegalovirus Cell culture (Davisstrain) Compound EC₅₀ (μg/ml) CC₅₀ (μg/ml) Compound No. 15 1.0 ≧250Compound No. 9  0.2 −< 0.4 ≧250 Tests in human embrionic lung cells(HEL). IC₅₀ = Inhibitory concentration to reduce virus plaque by 50%CC₅₀ = Cytotoxic concentration required to reduce HEL cell growth by 50%

TABLE 5 Activity of BRI compounds against miscellaneous viruses. MinimumInhibitory Concentration^(b) (μg/ml) Minimum Cytotoxic Herpes HerpesHerpes Herpes Concen- simplex simplex simplex Simplex tration^(a)virus-1 virus-2 virus-1 virus-1 Compound (μg/ml) (KOS) (G) TK-B2006TK-VMW1837 Compound ≧400 70  7 150 70 No. 4 Compound ≧400  7 20  20 20No. 20 ^(a)Required to cause a microscopically detectable alteration ofnormal morphology. ^(b)Required to reduce virus-inducedcytopathogenicity by 50%.

We claim:
 1. A composition (A) that displays antiviral activity in an invitro assay and (B) that comprises an dendrimer having a plurality ofterminal groups wherein at least one of said terminal groups has ananionic or cationic moiety, other than a 2-thiosialic acid moiety,bonded thereto.
 2. A composition according to claim 1, wherein saiddendrimer, comprises a polyvalent core covalently bonded to at least twodendritic branches, and extends through at least two generations.
 3. Acomposition according to claim 1, wherein said dendrimer is apolyamidoamine dendrimer based on an ammonia core.
 4. A compositionaccording to claim 1, wherein said dendrimer is a polyamidoaminedendrimer based on an ethylene diamine core.
 5. A composition accordingto claim 1, wherein said dendrimer is a polylysine dendrimer based on abenzhydrylamine or other suitable core.
 6. A composition according toclaim 1 wherein at least one of said anionic- or cationic-containingmoieties is bonded to terminal amine, sulfhydryl, hydroxy or otherreactive functional terminal group of said dendrimer by amide orthiourea linkages.
 7. A composition according to claim 1 wherein atleast one of said anionic-containing moieties is a sulfonicacid-containing moiety or carboxylic acid-containing moiety.
 8. Acomposition according to claim 1 wherein at least one of saidcationic-containing moieties is a trimethylammonium-containing moiety orpolyaminomacrocyclic-containing moiety.
 9. A composition to claim 1wherein at least one of the moieties which are bonded to amino or otherreactive functional terminal groups of the dendrimer is selected fromthe group Ar(COO—)_(n) consisting of —NH(CH₂)_(n)SO₃ ⁻—(CH₂)_(n)SO₃⁻—Ar(SO₃ ⁻)_(n) —CH₂CH(SO₃ ⁻)COOH—CH(SO₃ ⁻)CH₂COOH—ArX(CH₂)_(n)SO₃ ⁻X═O,S, NH —(CH₂)_(n) ⁺NMe₃—Ar(N⁺Me₃)_(n)—Ar(CH₂N⁺Me₃)_(n)

in which n is zero or a positive integer.
 10. A composition according toclaim 1 which is an alkylsulfonic acid terminated dendrimer.
 11. Acomposition according to claim 1 which is a sulfoacetamide terminateddendrimer.
 12. A composition according to claim 1 which is asulfosuccinamic acid terminated dendrimer.
 13. A composition accordingto claim 1 which is a N-(2-sulfoethyl) succinamide terminated dendrimer.14. A composition according to claim 1 wherein the moiety bonded to theterminal groups of the dendrimer is an aryl or heteroarylthioureasubstituted with at least one sulfonic acid group.
 15. A compositionaccording to claim 14 wherein the dendrimer is a 4-sulfophenylthioureaterminated group.
 16. A composition according to claim 14 wherein thedendrimer is a 3,6-disulfonapthylthiurea terminated dendrimer.
 17. Acomposition according to claim 14 wherein the dendrimer is a4-sulfonapthylthiourea terminated dendrimer.
 18. A composition accordingto claim 14 wherein the dendrimer is a 3,5-di-sulfophenylthioureaterminated dendrimer.
 19. A composition according to claim 14 whereinthe dendrimer is a 3,6,8-tri-sulfonapthylthiourea terminated dendrimer.20. A composition according to claim 1 wherein the moiety bonded to theterminal groups of the dendrimer is an aryl or heteroaryl amidesubstituted with at least one group selected from the group consistingof a sulfonic acid, a sulfoalkyl, a sulfoalkoxy, a sulfoalkylamino and asulfoalkylthio group.
 21. A composition according to claim 20 whereinthe dendrimer is a 4-(sulfomethyl) benzamide terminated dendrimer.
 22. Acomposition according to claim 20 wherein the dendrimer is a4-sulfobenzamide terminated dendrimer.
 23. A composition according toclaim 1 wherein the moiety bonded to the terminal groups of thedendrimer is an aryl or heteroaryl alkanamide substituted with at leastone sulfonic acid group.
 24. A composition according to claim 23 whereinthe dendrimer is a N-(4-sulfophenyl) propanamide terminated dendrimer.25. A composition according to claim 1 wherein the moiety bonded to theterminal groups of the dendrimer is an aryl or heteroaryl ureasubstituted with at least one sulfonic acid group.
 26. A compositionaccording to claim 25 wherein the dendrimer is a 4-sulfophenylureaterminated dendrimer.
 27. A composition according to claim 1 wherein themoiety bonded to the terminal groups of the dendrimer is anN,N,N-trimethyl derivative of an amino acid.
 28. A composition accordingto claim 27 wherein the dendrimer is a N,N,N-tri-methylglycinamideterminated dendrimer.
 29. A composition according to claim 1 wherein themoiety bonded to the terminal groups of the dendrimer is an aryl orheteroaryl amide substituted with a group selected from the groupconsisting of trialkylamino, trialkylaminoalkyl, trialkylaminoalkyloxy,trialkylamioalkylamino and trialkylaminoalkylthio group.
 30. Acomposition according to claim 29 wherein the dendrimer is a4-trimethylammonium benzamide terminated dendrimer.
 31. A compositionaccording to claim 29 wherein the dendrimer is a 4-(trimethylammoniummethyl) benzamide terminated dendrimer.
 32. A composition according toclaim 1 wherein the dendrimer is aN-(2-acetoxyethyl-N,N-(dimethylammonium) methylcarboxyamide terminateddendrimer.
 33. A composition according to claim 1 wherein the dendrimeris a guanidino terminated dendrimer.
 34. A composition according toclaim 1 wherein the dendrimer is a macrocyclic polyamino groupcomprising a macrocyclic ring connected through an alkyl or aryl spacermoiety to the terminal group of the dendrimer.
 35. A compositionaccording to claim 34 wherein the dendrimer is a4-([1,4,8,11-tetra-azacyclotetradecane]methyl)benzamide terminateddendrimer.
 36. A composition according to claim 1 wherein the dendrimeris a 4-carboxy-3-hydroxbenzylamine terminated dendrimer.
 37. Apharmaceutical or veterinary composition for prophylactic or therapeuticantiviral treatment of a human or non-human animal, which comprises acomposition of claim 1, in association with at least onepharmaceutically or veterinarily acceptable carrier or diluent.
 38. Amethod for prophylactic or therapeutic antiviral treatment of a human ornon-human animal, which comprises administering to said human or animalor prophylactic- or therapeutic-antiviral-effective amount of acomposition of claim
 1. 39. A method according to claim 38, wherein saidantiviral treatment is treatment of infection by a virus selected fromthe group consisting of HIV1, HIV2, Hepatitis B virus, Hepatitis Cvirus, Bovine Viral Diarrhoea Virus, Human Influenza Virus B,Rhinovirus, Human Parainfluenza Virus, Respiratory Syncytial Virus(RSV), Varicella Zoster Virus (VSV), Human Cytomegalovirus (CMV),Epstein Bar Virus (EBV), Human Papilloma Virus (HPV), Adenovirus, HerpesSimplex Virus type 1, Herpes Simplex Virus type 2, Measles Virus, andVesicular Stomatitis Virus (VSV).
 40. A composition according to claim1, wherein the antiviral activity is against a virus selected from thegroup consisting of HIV1, HIV2, Hepatitis B virus, Hepatitis C virus,Bovine Viral Diarrhoea Virus, Human Influenza Virus B, Rhinovirus, HumanParainfluenza Virus, Respiratory Syncytial Virus (RSV), Varicella ZosterVirus (VSV), Human Cytomegalovirus (CMV), Epstein Barr Virus (EBV),Human Papilloma Virus (HPV), Adenovirus, Herpes Simplex Virus type 1,Herpes Simplex Virus type 2, Measles Virus, and Vesicular StomatitisVirus (VSV).